I thought I'd solved it, but all the clues were red herrings. The fingerprint was thought to be a key clue, but it turned out to be a red herring that misled the investigation. 4. “in the red” 负债 If ...

Red carpets were traditionally used for welcoming royalty and heads of state, though these days they are often used for celebrity events. The earliest reference to a 'red carpet' in this sense was is ...